Routing to a Buss

Yea, what Sean said.
 
Along the same lines, I'm wondering what folks do with the outputs of their effect return busses? I have problems sometimes in that usually I send the outs of these busses to the master, But, if there is any processing on the other instrument subgroups, I tend to get artifacts, or oddness, out of the effect busses because the sends of those instruments usually come from the track sends . Hope that makes sense.

back in the old days when all I had was a 4 track recorder, this was really the only option.
you had 2 sends on each track. All outputs of those 4 tracks went to the master bus.

as you can see in the example above. going from bottom to top= there is a volume / pan / 2 sends
on each track. don't be misunderstood this is NOT an 8 track (5-6+7-8) Those last 2 faders (to the right)
were stereo inputs used in conjunction with the 2  1/4 inch jack sends located on the back.
in other words, you hooked up your hardware's outputs to 5 thru 8.
-The sends controls the amount of signal that goes to your hardware (the input).
-The faders controls the amount that comes from the hardware (output).
 
so now we go to a realistic approach in something like Sonar.
you typically never use a send for something like compression. unless of course your using it as an effect.
IE= Parallel Compression. 
You will however find a send is very productive in FX like Delay, Reverb, Chorus, Flange.
 
Example=
lets say I have 3 vocal tracks (1 lead vox / 2 background vox) 
I want the lead vocal to have a good amount of reverb but I don't want the background vocals to have as much.
(you want to be able to distinguish the tracks. putting the same amount of reverb to all 3 vocal tracks will make them muddy and dare I say: blurry.)
there is no way possible to accomplish this using a bus. your only other option is to put a single reverb FX on each individual track. which lets face it, that is chewing up CPU.
so what we do is:
 
1-create a bus.(set the bus output to the master)
2-insert a reverb in to the FX bin of the bus.
3-insert a send to each of the 3 vocal tracks (the 1 lead vox / 2 background vox).
4-turn the lead vox send to around 5 o'clock.
5-turn the 2 background vox sends to 3 o'clock.
 
taking it one step further, you can automate the sends. which IMO is one of the best parts
about using sends vs. a bus.
if there's a long vocal note. apply automation to crank up the send during just that one part.
of course all the while being thoughtful and aware of what too much reverb does (drowns the sound).
 
Sends are critical in saving resources and mastering the tool.